In the related art, as a lighting device of this type, for example, the one described in Patent Document 1 shown below is known. The lighting device described in Patent Document 1 includes a light source unit having a light source (LED) mounted (disposed) on a substrate as a circuit board, a liquid crystal display panel (lighted member) to be lighted by an illuminating light beam from the light source, a case member arranged between the substrate and the liquid crystal display panel and formed of a synthetic resin having a cavity portion provided so as to correspond to the light source, and a diffusing member interposed between the case member and the liquid crystal display panel and placed on the case body.
Then, in this case, the case body are placed on the substrate so as to surround the light source, and the diffusing member and the liquid crystal display panel is arranged on the case body in a stacked manner so that the liquid crystal display panel is positioned at an uppermost position. In other words, it means that the substrate of the light source unit is disposed so as to close an opening on a lower end side of the cavity portion and the diffusing member (the liquid crystal display panel) is disposed so as to close an opening on an upper end side of the cavity portion on the opposite side from the opening on the lower end side.
In this configuration, the illuminating light beam emitted from the light source passes the cavity portion, which corresponds to the inner portion of the case member, is substantially uniformized through the diffusing member placed on the case body, and the uniformized illumination light beam lights through the liquid crystal display panel placed on the diffusing member. Accordingly, the liquid crystal display panel is lighted by a back light.